​A courier delivering medical marijuana to what he thought was a dispensary was mugged for $20,000 worth of cannabis by three men, according to police in Fullerton, California.

Police said the trio set up a fake medical marijuana dispensary in a commercial building in Fullerton, even painting a green cross on the outside wall of the building, reports Dennis Romero at LA Weekly.

“These suspects had spent some time putting this ruse together, putting the order in and finding a building that worked for what they were trying to do,” said Sgt. Andrew Goodrich of the Fullerton Police Department,